The present invention relates to a timed switch, and more particularly, to a timed switch, which can be fitted to all sorts of appliances, and can work together with other types of protective switches such as temperature switches to provide double protection so as to prevent accident from happening if the other types of protective switches fail to work properly.
Over the years, many protective switches have been developed to satisfy the need for a automatically turning off the appliances, such as timed switches which can turn off the appliances, after they have been actuated for a preselected time such that the appliances will not work too long and cause danger.
Other protective switches include temperature switches, which can automatically turn off the appliances when the same overheat. All of these protective switches are easy to use, and prevent many dangerous events from happening but people often neglect to maintain the protective switches while continuing to rely on them just because they are very convenient. An accident is likely to happen when the protective switches break down without anybody being aware of it.
Therefore, it would be a good idea to have a timed switch which can be easily fitted to an appliance and connected to the original protective switch of the appliance such that the appliance is provided with double protection.
Therefore, it is a main object of the present invention to provide a timed switch, which can be easily fitted to an appliance, and connected to other protective switches of the appliance to provide double protection. And, it is another object of the present invention to provide a timed switch, which is easy to use and doesn""t have the drawbacks of conventional ones.
The timed switch of the present invention includes a housing member, first, second, and third connecting legs, a control button, and a circuit board.
The housing member has a front part and a rear part. The first connecting leg has a front end contacting portion disposed behind the front part, and have a rear end connecting portion sticking out from the rear part of the housing member for electrical connection with a power supply.
The circuit board includes an electromagnet and a timing device. The circuit board is received in the housing member, and is electrically connected to a second connecting leg having a rear end sticking out from the rear part of the housing member. The timing device can make the circuit of the circuit board become open at a preselected time after same has been energized.
The third leg has a connecting part having a rear end sticking out from the housing member for electrical connection with the input terminal of an appliance, and a vertical part disposed behind the front part of the housing member; the vertical part has an upper end, and a lower end disposed behind the contacting portion of the first leg, and in front of the electromagnet respectively. The third leg is further electrically connected to the circuit board.
The control button has a power-off upper end, and a power-on lower end, and is pivoted to the front part of the housing member at a middle with an upper, and a lower pushing protrusions passing through the front part to abut the upper, and the lower ends of the vertical part.
Thus, the appliance can be energized when said power-on end is pushed so as to make the lower end of the vertical part come into contact with the electromagnet plus make the upper end of the vertical part come into contact with the contacting portion of the first leg; the circuit board becomes complete for both the electromagnet, and the timing device to be actuated to attract the lower end of the vertical part thereto, and to automatically turn off the appliance at the preselected time respectively.